Laserfiche WebLink
- 43 <br /> estimates were made for each plot with conditions which existed at time <br />• of sa <br />li <br />il <br />i <br />b <br />d <br />t <br />l <br />i <br />i <br /> mp <br />any so <br />eros <br />on compar <br />sons <br />ween coa <br />ng, an <br />e <br />reg <br />ons are <br /> difficult because of complexity caused by management factors. For ex- <br /> ample, Energy Fuels No. 3 was seeded in 1976 and had a dense stand of <br /> vegetation at the time of sampling, reflected in very low C values, but <br /> Delagua was seeded in 1980 and had high C factors (see Appendix D). <br />' Several years after the sampling date when vegetation has had time to be- <br /> come established at Delagua the disparity between the estimated soil <br />' losses will probably decrease. With the limited sampling of this study <br /> and the complexity caused by management factors at the time of sampling, <br /> few statistically sound conclusions can be drawn comparing erosion po- <br />I tentials of regraded lands between coal regions from Table 5. <br /> A fairer comparison of actual soil erosion characteristics of coal <br />I • fields and coal regions might be soil losses estimated by the basic equa- <br />l tion, A = R x K (Table 6). The factors affected most by management <br /> practices are eliminated, although the ground cover factor, C, is undoubt- <br /> edly affected by climate and soils as well as by management, and the soil <br /> erodibility factor, K, may be affected by the amount of topsoil saved and <br /> methods of regrading (compaction). The mean sail losses estimated by the <br /> basic equation (Table 6) are all higher than the mean soil losses esti- <br /> mated by the complete equation (Table 5) with the exception of Delagua. <br /> This discrepancy is primarily due to high LS factors at Delagua (see <br /> Appendix D). The sampling sites, ranked by mean estimated soil loss <br /> using the basic equation (Table 6), are grouped more by coal regions <br /> than when the manageahle factors are included (Table 5). The differ- <br /> ences between the mean estimated soil losses of Table 5 and Table 6, <br />. demonstrate particularly the extent of influence of mined land reclama- <br /> tion practices on soil loss. <br />